1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
/*
* The Computer Language Shootout
* http://shootout.alioth.debian.org/
*
* contributed by Andrei Formiga
*/
object recursive
{
def ack(x: Int, y: Int): Int =
if (x == 0) y + 1
else if (y == 0) ack(x - 1, 1)
else ack(x - 1, ack(x, y - 1))
def fib(n: Int): Int =
if (n < 2) 1 else fib(n - 2) + fib(n - 1)
def fib(n: Double): Double =
if (n < 2.0) 1.0 else fib(n - 2.0) + fib(n - 1.0)
def tak(x: Int, y: Int, z: Int): Int =
if (y < x) tak(tak(x - 1, y, z), tak(y - 1, z, x), tak(z - 1, x, y))
else z
def tak(x: Double, y: Double, z: Double): Double =
if (y < x) tak(tak(x - 1.0, y, z), tak(y - 1.0, z, x), tak(z - 1.0, x, y))
else z
def main(args: Array[String]) {
var n = Integer.parseInt(args(0))
// spawn a new thread fixes stack overflows on Windows 1.5 JDK
// see more on ticket #1508
val t = new Thread {
override def run {
Console.println("Ack(3," + n + "): " + ack(3, n))
Console.printf("Fib(%.1f): %.1f\n", (27.0+n), fib(27.0+n))
n = n - 1
Console.println("Tak(" + (3*n) + "," + (2*n) + "," + n + "): " + tak(3*n, 2*n, n))
Console.println("Fib(3): " + fib(3))
Console.println("Tak(3.0,2.0,1.0): " + tak(3.0,2.0,1.0))
}
}
t.start()
t.join()
}
}
|
